Complete information regarding the neural mechanisms regulating pituitary secretion of luteinizing hormone (LH), follicle stimulating hormone (FSH) and prolactin is still lacking, although it is well established that the central nervous system participates in the regulation of reproductive function in man. Evidence has now accumulated indicating that the hypothalamus contains releasing- and inhibiting-factors which control the rates of syntheses and secretion of pituitary hormones. Recent studies suggest that certain amino acids may act as neurotransmiters in the mammalian nervous system. However, the neurally-active amino acids have not been considered as possible candidates in controlling pituitary hormone secretion. Recent studies from this laboratory have indicated that GABA, glycine, glutamate, lysine & taurine can affect pituitary secretion of LH and prolactin in the male rat. The objective of the present study is to ascertain more completely the role of neurally-active amino acids in reprocuctive processes. BIBLIOGRAPHIC REFERENCES: Pass, K.A. and J.G. Ondo. A Dual Cerebroventricular and Vascular Cannulation Technique for Use in Conscious Rats, Physiology and Behavior 18: 173-175 (1977). Pass, K.A. and J.G. Ondo. The Effects of gamma-Aminobutyric Acid on Prolactin and Gonadotropin Secretion in the Unanesthetized Rat, Endocrinology 100:1437-1442 (1977).